VACTERL association is a congenital disorder that was named using an acronym: Vertebral defects, Anal atresia, Tracheo-Esophageal (TE) fistula with esophageal atresia, Radial and Renal dysplasia, and Limb anomalies. Since these early descriptions, the definition of VACTERL association in the medical literature has been problematic for a number of reasons. Here we propose a detailed clinical evaluation of patients with this birth defect at the NIH Clinical Center to better define the phenotype of this association. To identify the underlying genetic etiologies, we propose multiple genetic tests including candiate gene testing and and genomic (eg, whole exome and whole genome) sequencing in selected patients. Identification of genes involved in the etiology of VACTERL association will increase our understanding of normal and abnormal development during early embryogenesis.